Transient Response of a Carburetor Engine

The transient response of a carburetor engine was studied experimentally. The results show that fuel and air flow at the carburetor respond instantly to throttle motion, however at the cylinder, dynamic lags in fuel flow make large variations in air fuel ratio which appear as delays in the change in maximum cylinder pressure. Initial air fuel ratio has a large effect on this maximum cylinder pressure response, and its time lags vary in proportion to inlet pipe length and inversely proportion to engine speed.

An approximate theory on the fuel film flow was established to explain these results.